diff --git a/mod/lti/db/install.php b/mod/lti/db/install.php
index 9adf9db60ba..e70c95c55c2 100644
--- a/mod/lti/db/install.php
+++ b/mod/lti/db/install.php
@@ -28,11 +28,6 @@ defined('MOODLE_INTERNAL') || die();
  * Stub for database installation.
  */
 function xmldb_lti_install() {
-    global $CFG;
-
-    // Add platform ID configuration setting.
-    set_config('platformid', $CFG->wwwroot, 'mod_lti');
-
     // Create the private key.
     $kid = bin2hex(openssl_random_pseudo_bytes(10));
     set_config('kid', $kid, 'mod_lti');
diff --git a/mod/lti/db/upgrade.php b/mod/lti/db/upgrade.php
index 135bc2950c8..4908f6cc3e4 100644
--- a/mod/lti/db/upgrade.php
+++ b/mod/lti/db/upgrade.php
@@ -157,9 +157,6 @@ function xmldb_lti_upgrade($oldversion) {
             $dbman->add_index($table, $index);
         }
 
-        // Add platform ID configuration setting.
-        set_config('platformid', $CFG->wwwroot, 'mod_lti');
-
         // Create the private key.
         $kid = bin2hex(openssl_random_pseudo_bytes(10));
         set_config('kid', $kid, 'mod_lti');
diff --git a/mod/lti/locallib.php b/mod/lti/locallib.php
index 3bd9a2a0ca3..f7e665ab288 100644
--- a/mod/lti/locallib.php
+++ b/mod/lti/locallib.php
@@ -3018,6 +3018,7 @@ function lti_sign_parameters($oldparms, $endpoint, $method, $oauthconsumerkey, $
  * @return array|null
  */
 function lti_sign_jwt($parms, $endpoint, $oauthconsumerkey, $typeid = 0, $nonce = '') {
+    global $CFG;
 
     if (empty($typeid)) {
         $typeid = 0;
@@ -3054,7 +3055,7 @@ function lti_sign_jwt($parms, $endpoint, $oauthconsumerkey, $typeid = 0, $nonce
         'iat' => $now,
         'exp' => $now + 60,
     );
-    $payload['iss'] = get_config('mod_lti', 'platformid');
+    $payload['iss'] = $CFG->wwwroot;
     $payload['aud'] = $oauthconsumerkey;
     $payload[LTI_JWT_CLAIM_PREFIX . '/claim/deployment_id'] = strval($typeid);
     $payload[LTI_JWT_CLAIM_PREFIX . '/claim/target_link_uri'] = $endpoint;
@@ -3264,7 +3265,7 @@ function lti_post_launch_html($newparms, $endpoint, $debug=false) {
  */
 function lti_initiate_login($courseid, $id, $instance, $config, $messagetype = 'basic-lti-launch-request', $title = '',
         $text = '') {
-    global $SESSION, $USER;
+    global $SESSION, $USER, $CFG;
 
     if (!empty($instance)) {
         $endpoint = !empty($instance->toolurl) ? $instance->toolurl : $config->lti_toolurl;
@@ -3284,7 +3285,7 @@ function lti_initiate_login($courseid, $id, $instance, $config, $messagetype = '
     }
 
     $params = array();
-    $params['iss'] = get_config('mod_lti', 'platformid');
+    $params['iss'] = $CFG->wwwroot;
     $params['target_link_uri'] = $endpoint;
     $params['login_hint'] = $USER->id;
     $params['lti_message_hint'] = $id;
@@ -3839,7 +3840,8 @@ function get_tool_type_state_info(stdClass $type) {
  * @return array An array with configuration details
  */
 function get_tool_type_config($type) {
-    $platformid = get_config('mod_lti', 'platformid');
+    global $CFG;
+    $platformid = $CFG->wwwroot;
     $clientid = $type->clientid;
     $deploymentid = $type->id;
     $publickeyseturl = new moodle_url('/mod/lti/certs.php');
@@ -3940,7 +3942,7 @@ function serialise_tool_type(stdClass $type) {
         'description' => $description,
         'urls' => get_tool_type_urls($type),
         'state' => get_tool_type_state_info($type),
-        'platformid' => get_config('mod_lti', 'platformid'),
+        'platformid' => $CFG->wwwroot,
         'clientid' => $type->clientid,
         'deploymentid' => $type->id,
         'hascapabilitygroups' => !empty($capabilitygroups),